Automatic fire -alarm



Noy. 2,1926. 1,605,260

0- WL MERRIAM 1 AUTOMATIC FIRE ALARM Filed Feb. .25, 1924 27 @M' w- WPatented Nov, 2, 1926.

035212 w. MERRIAM, or OGDEN, IOWA.

AITTOMATIG FIRE ALARM.

Applicationfiled February 25, 1924. Serial No, 695,052.

The object of my invention is to provide an -'autom-atic fire alarmsystem of simple, durable and inexpensive construction which may beeasily and quickly installed, and which when installed will be reliableand positive in its action, and one which needs but a minimum amount ofattention to always keep it in a working condition.

My invention consists in the construction, arrangement and combinationof the various parts of the device, whereby the Dbjects contemplated areattaiI-led, as hereinafter more fully set forth, ppinted out in myclaim, and illustrated in the accompanying drawings, in which: v H 1Figure 1 is a diagrammatieal view illustrating improved system. i 1

Figure 2 is a segmental top view 'ofb'ne of the controlling switchdevices, and also a portion of the variable resistance.

Figure 3 is an end elevation 'of the" same.

Figure 1 is a sidev elevation of one of the primary switch devices.

This, system is designed to operate preferably fror'n theelectric lightlines of the town in which the alarm is operated,

The numeral 10 indicates the main lines of an electric lighting; system.I have connected with each of the conductors of the said lines,conductors 11 and 12 ahcl revided a third conductor which runs parallelwith the right angle extending portions of said conduct'ors 11 and 12.Connecting -the conductors 12 and 13 is a series of thermostaticallycontrolled switch deyices 1 1'. These switch devices may be placed inany pesiti'oh in the b ilding in which it is desired to installtheapparatus, 'or' in such rooms as are to be protected by the fire alarm.-Q

EElCh-Of the switches 14c 001111511895; it Tillie member 15forined'"snbstantially U-s'h'ape'd and has between its perallel membersa then isostatic water 16 hi that type hich will very readily by chan eor the or three degrees in temperature. One side of the wafer 16 issecured to the leg member 1'7,

er the frame "10, while the underside of the wafer 16 is provided with adownwardly jex tending pin 18 slitlahly meuhteel in the free endof theleg member 19 of the frame 15.

The leg member 19 is provided with a downwardly extending arm 20 inwhich is mounted a contact member 21 formed of spring material andhaving spaced fingers 22 so arranged that as the wafer 16 expands, thepin 18 will be moved downwardly and in the buil'dingwhere it willattract the a'ttention of passersby, thereby giving a signal that fireis takingplajce somewhere within the building. Any number of these lampsmay be provided. One might be placed in the firestation also, if"desired. 1 Between the conductors 11 and 13 and parallel with the lamp25, I have provided what I shall term a the'rm'o-electricswitchcl'osin-g' "device comprising an electric heating element 26,which may consist of a plate 27 formed of insulating material over whicha series bf resistance wires 28 is mounted in a zig-za'g manner, similarto the heating elements of electric cookers. One side of the heatingelement is connected to the conductor 13, while the other side isconnected to a conductor 29. This conductor 29 has includeda knifeswitch 30 and is connected with the conductor 11, thereby completing thecir cuit through the heating element 26 when both of the switches 2 1and 30 have been closed. a

A second thermostatic wafer '31 is mounte'd immediately above the member26 so that it will be actuated by the heat therefrom. This wafer 31isprovided with an upwardly extending post 32 designed to carry" an insulated block 33 which has two upwardly projecting pins 34, each ofwhichis designed to make contact with a set of flexible fingers 36 soarranged that as the wafer 31 is "expanded, the pins 34 will be slidablyreceived between the said finger contacting member's, thereby insuringaperfect connection.-

The fingers 35 and the ltnife switch 30 are mounted on suitable support36 which is constructed of any suitable insulating material. The switch30 comprises contact mem bers 37 and 38, the member 38 being pivoted andfree to swing in'sliding contact with the member 37 The said member 37is extended and pivotally and adjustably connected with the upper end ofthe rod 32, so that when the wafer 31 has been expanded a pre-determinedamount, the switch may be opened and the circuit through the heater 26disconnected. This is for the purpose of preventing the wafer expandingto such an ex-' tent that it will be in danger of bursting. As soon asthe thermostat has cooled, the switch 30 will again be closed. The pins34 are of such length that the switch 30 may be opened and closedwithout opening the contact between the pins 34 and the fingers 35.

One of the contact members 35 is connected with a conductor 39, whilethe other is connected with a conductor 40. Said conductors 39 and 40being connected with conductors 41 and 42 respectively. The saidconductors form an alarm circuit in which is included an alarm device43. The conductors 41 and 42, however, are assumed to be conductors ofthe telephone line which leads from the central telephone ofiice to theresi dence or building in which the alarm is established. The alarmcircuit is completed by providing a conductor 44, one end of which isconnected with one of the posts 34 and leads to a variable resistance45. One end of said resistance is connected to the conductor 13. Theother post 34 is provided with a conductor 46 which is connected with avariable resistance 47 similar to the resistance 45, said resistancemaking connection with the conductor 11.

Thus it will be seen that if one of the thermostatic switches is closed,the heating element 26 will be heated through the conductors abovedescribed, which will cause the thermostat 31 to be expanded and thepost 34 to make contact with the fingers 35. This will then establish acircuit first through the resistance 45,'the conductor 44, the post 34and the corresponding contact member 35, the conductor 39. the alarm 43,the conduc tors 42 and 40, the contact 35, the post 34, the conductor 46and the resistance 47.

Inasmuch as the regular lighting system is usually of no less than onehundred 'ten volts, and usually an alternating current, it will be seenthat the variable resistance devices and 47 may be so adjusted thatvoltage may be produced of sufficient intensity to operate the ringingmechanism of the ordinary telephone system, to thereby give an alarm tothe telephone operator, or if the system is that type which employs adrop, the same will be operated and the correspondinglamp 25 lighted. Inthe latter case the signal lamp 25 may be placed in a suitable box apartfrom the regular switch board, each thermostatic control system havingits own lamp. The name of the building in which the system is installedis inserted opposite the lamp. The operator will then be able toascertain where the fire is located. The telephone operator may thengive alarm to the various members of the fire department. This systemapplies chiefly to small towns which do not have a regular firedepartment and depend upon volunteer service. It will be seen, however,that a bell maybe substituted for the regular telephone bell which maybe placed in the fire department headquarters if so desired, withoutmaterially changing the system.

By providing two of the variable resistances 45 and 47, each of whichmakes connection with the conductors of the main line, I have providedmeans whereby, it either of the conductors 44, 46, 39 or 40 were to become grounded, it would not be possible for a sufiicient current to gothrough the other side of the system so as to burn out the telephonecoils.

It will be seen that my system is so constructed that the lamp 25 andthe alarm system are capable of being arranged in numerous ways whichwould work out most advantageously to the community in which the alarmsystem was installed. That is, the lamp 25 might be placed in front ofthe building in which the system was installed, or it might be placed inthe main fire department oflice, or there might be a lamp both in frontof the building and another one in the fire department olfice. Anynumber of lamps may be used between the conductors 13 and 11.

It will be seen that by this arrangement I have provided an alarm systemwhich is quite positive in its action and one in which the upkeep isreduced to a minimum, and one in which the expense of installation isalso small, due to the fact that the wires of the system alreadyinstalled are utilized to form a part of my improved system.

I claim as my invention:

An alarm system comprising an alternat-' ing current power circuit, analarm circuit in parallel therewith and including an alarm device,thermostatically controlled means for closing said alarm circuit, atelephone circuit, a pair of conductors for connecting said telephonecircuit in parallel with said alarm circuit, each of said conductorsincluding a variable resistance and a switch, a thermoelectric device insaid alarm circuit for closinp; said switches when the said alarmcircuit has been closed.

Des Moines, Iowa, February 14, 1924.

ORTIZ W. MERRIAM.

